The Maine state fire marshal’s office announced the death of Searsmont Assistant Fire Chief Wayne Woodbury on Sunday morning at Maine Medical Center in Portland.

Woodbury, 76, suffered serious injuries after responding to a devastating fire on May 15 at Robbins Lumber in Searsmont.

The fire and explosion at the lumber yard killed another firefighter, 27-year-old Morrill firefighter Andrew Cross, and injured at least 10 other people, several of whom remain hospitalized.

Robbins Lumber resumed operations at its Searsmont yard on May 26.

The fire remains under investigation. It broke out about 10:05 a.m. in an area of the lumber yard where wood shavings are packed in plastic bags. That blaze reportedly spread to a silo filled with sawdust that exploded about 11 a.m. as firefighters were nearby.

A joint federal-state investigation is underway to determine the cause of the fire and explosion. It was hampered in the days immediately after the blast because of high winds.

Investigators said the silo exploded before the fire suppression system could be triggered. The blast lifted the silo off its concrete base.